Cooling ceiling installations are particularly known from modern office buildings. As cold air will fall down, a cooling ceiling offers a good opportunity of reducing the air temperature in an agreeable manner, that is, substantially without draught. For this purpose, a heat transfer medium, for example cold water, is led through the heat exchanger, which is located in the room ceiling. The air skimming across the heat exchanger transfers heat to the heat exchanger, that is, is cooled down.
However, problems with condensing water sometimes occur in connection with cooling ceilings. In office buildings, cooling ceilings are typically located above desks, computers and other workplaces. When air humidity condenses and gathers on the heat exchanger of the cooling ceiling, water can drop down, which is regarded to be unpleasant, when the drops hit a person. Dangerous situations may occur, when the drops penetrate into electrical devices, like computers and the like, and cause damage.
Therefore, a monitoring device against condensate formation has been provided. Such a monitoring device is, for example, described in the brochure “Massgeschneiderte Regellösungen für Kühl- und Heizstrahldecken” of the Zent-Frenger Gesellschaft für Gebäudetechnik mbH, D-64646 Heppenheim. With increasing room temperature, the valve controlling the flow of the heat transfer medium through the heat exchanger, is opened. Such a system is typically dimensioned for an inlet temperature of 14° C. and a return temperature of 16 to 19° C. With higher air humidity, there is, as mentioned above, a risk of condensed water formation on the cooling ceiling. This risk is not eliminated in that the valve is controlled, for example via a thermostatic controller. In order to counteract the condensate formation, the known case combines the room temperature control in an electronic manner with an integrated condensate monitoring. In principle, there are two different control forms. Measuring of the dew-point or the relative air humidity are made currently, and when a critical point is reached, the inlet temperature is increased, that is, an active condensate monitoring, or the valve is closed, so that the cooling ceiling is “turned off”, that is, a passive condensate monitoring.
Common for both solutions is that they require the running of cables, which makes the installation more expensive and reduces the flexibility of the system. When it is desired to control the room temperature with an independent controller, a separate, active or passive condensate monitoring function must be established, which again makes the installation more expensive.